e performed studies aimed at delineating the mmunopathogenesis of a diversity of immune-mediated diseases nd/or diseases characterized by aberrancies of immune unction. We phenotypically characterized the T lymphocyte ubsets infiltrating the thyroid glands of patients with raves' disease and demonstrated that these glands were ifferent from normals in that the follicular epithelium was nfiltrated with a population of mononuclear cells comprised lmost entirely of T cells with the T8 suppressor phenotype. e also studied the functional capabilities of T cells from raves' disease patients at the clonal level. We determined he mechanisms for the hemophagocytosis observed in ngiocentric lymphoproliferative diseases by demonstrating that alignant T cells from such patients secrete a phagocytosis nducing factor, which we have characterized and which ctivates human monocyte/macrophages to phagocytose. We eveloped Epstein-Barr virus (EBV)-transformed B cell lines rom patients with the Chediak-Higashi syndrome and chronic ranulomatous disease and demonstrated that these B cell lines anifested the precise metabolic defects as the phagocytic ells in these diseases. We identified and purified to omogeneity the components of the human eosinophilic granule ncluding major basic protein, eosinophilic protein, and osinophil-derived neurotoxin. These factors play a major role n the pathogenesis of the tissue damage in the idiopathic ypereosinophilic syndrome. We delineated the potential echanisms of the B cell hyperactivity in Sjogren's syndrome nd initiated studies on the natural history, pathogenesis, and herapy of idiopathic dilated cardiomyopathy.